| 1 | English | unreasonable | Without the ability to reason; unreasoning; Not... |
| 2 | English | reason | A cause; Rational thinking ; the cognitive... |
| 3 | Middle English | resoun | resound; reason |
| 4 | Anglo-Norman | raisun | Alternative form of reson |
| 5 | Old French | reson | logic, logical reasoning |
| 6 | Latin | ratiō | — |
| 7 | Latin | -tiō | — |
| 8 | Latin | dissertātiō | — |
| 9 | Latin | dissertus | arranged, disposed; explained |
| 10 | Latin | disserere | second-person singular future passive indicative... |
| 11 | Latin | dis- | asunder, apart, in two; reversal, removal;... |
| 12 | Latin | calceus | shoe |
| 13 | Latin | calx | limestone; chalk; the finish line |
| 14 | Ancient Greek | χάλιξ | small stone, pebble; gravel, rubble |